speaker not working anymore

hello, i need help fixing my headset, the right ear stopped working, i opened it up and noticed that little chip that is glued to the speaker unglued, i tried re-gluing it but it still doesn't work.

i unglued the one on the left earphone to try to understand the issue, but once i put it back the left one doesn't work!

how exactly do headphones work? could it be that it wasn't just glue? (it sure looks like it! and it wasn't solder or anything conductive i think)

check pictures : https://imgur.com/a/LT20EqA